Review originally in Population and Development Review. Reproduced with permission of the reviewer.

For the academic readership that is its primary target, Marriage and Cohabitation is a careful, methodical, intricate piece of work by three very able social scientists. In tapping the potential of a unique longitudinal, intergenerational dataset, it greatly enhances our understanding of the processes by which young Americans formed heterosexual unions in an era when cohabitation and marriage had come to compete with each other as forms of union. For the general reader who might be intrigued by the subject, however, the book will be challenging. Much methodological material is appropriately sequestered in appendixes, but still a significant level of statistical expertise is demanded.

The primary data source used is the Intergenerational Panel Study of Parents and Children (IPS), which began in 1962 by interviewing 1,113 white mothers in the Detroit metropolitan area, approximately equal numbers of whom had recently given birth to first, second, and fourth children. Mothers were interviewed eight times between 1962 and 1993, and their children three times (at ages 18, 23, and 31). Some 950 mother/child pairs remained in the study throughout its 31-year duration. Although the study is geographically localized, the state of Michigan approximates the national median on summary indexes of marital and cohabiting behavior. The authors are sensitive to the omission of minority racial groups, addressing this issue explicitly at the end of each analytic chapter.

"[T]he declining centrality of marriage in defining and guiding human behavior and relationships" is identified as "[o]ne of the most important stories of the past several centuries of Western history" (p. 4). Noting that the pace of change over recent decades has been especially rapid, the authors pose three broad research questions about their subject: What forces have stimulated the transformation in how Americans organize their personal and intimate lives? What are the consequences of the changes for individuals and the wider society? And what forces are producing the modern diversity in attitudes and behavior in courtship, marriage, divorce, cohabitation, sex, and childbearing? The primary focus of Marriage and Cohabitation is on the third question, investigating the ways in which young people's marriage and cohabitatio n decisions are influenced by personal circumstances, experiences, and attitudes, and by their larger family setting. The first question is touched on through an evaluation of the characteristics of some central participants in the changing pattern of union formation—although the single-cohort IPS data are not well-suited to explaining change.

An early chapter reviews the European roots of American marriage. In the centuries prior to 1800, marriage was "a deeply gendered institution" whose economic prerequisites took time to attain. Nonetheless, young people, especially in the less privileged classes, "had remarkable freedom in courtship and mate selection" (pp-30, 34), with church and state involvement less than often assumed. From the nineteenth century on, marriage gradually lost its central role in structuring and defining adult life. Independent living, household headship, and a good job eventually became attainable without it. The ideals of individual freedom, equality, and consent that lay behind the American and French revolutions and the abolitionist movement came to permeate marriage and family life as well.

Cohabitation, the authors argue, is a distinct relationship status, additional to marriage and being single. They explore how cohabitation relates to those other two statuses and, importantly, its marked heterogeneity as a form of union. In detailing the union formation process, they present a number of alternative conceptualizations of transitions between relationship statuses and trace transition rates and patterns for the IPS children.

The central part of the study consists of two groups of chapters mining the IPS data, the first exploring intergenerational influences on union formation, the second exploring influences, both parental and child, associated with the children having become young adults. The authors examine the effects of parental upbringing and circumstances on the IPS child at birth and during childhood and adolescence, looking at, among other things, parents' socioeconomic status, size of family, maternal employment, religious background, recent immigration, and family social interactions. Nearly all dimensions of the parental family examined are found to be related to children's union-formation experience. Parental attitudes matter too: a complex analysis of intergenerational influence on union formation finds "significant independent effects on children's behavior of a broad range of parental attitudes" (p. 237). The study finds no support for the proposition that the strength of the influence of parental attitudes on children's behavior is a function of the quality of the parent-child relationship.

A chapter examines the influence of religion. Highly religious young people generally enter their first coresidential unions at a similar rate to others, but are more likely to choose marriage over cohabitation. Religiosity is transmitted across generations: parents have been socialized by their own parents and then pass on their religiosity to their children. The inhibiting force of religiosity on cohabitation is strongest when a couple has no plans for marriage and weakest when the partners are engaged to be married. Religious attendance, importance, and belief are stronger influences than religious affiliation.

The authors spend substantial time identifying how union formation is affected by the attitudes of young people themselves—attitudes toward premarital sex and cohabitation, marriage and divorce, childbearing, abortion, education, careers, luxury spending, and sex roles. The task calls for trying to disentangle direct from indirect effects and for dealing with the "intertwining" of often highly correlated attitudes.

Because early studies of cohabitation were often set on college campuses, the idea arose that cohabitation was associated with tertiary education. The authors dispel that myth, showing that, consistent with their theory, rates of both cohabitation and marriage are lower among those enrolled at educational institutions. Also consistent with theory, the negative impact of School enrollment is more modest on cohabitation than on marriage, and the effect on marriage declines across the life course. Educational attainment is associated with higher rates of marriage, and lack of it with higher rates of cohabitation.

Variables focused on work and earning capacity provide another set of interesting findings. Being employed is associated with faster entry to both marriage and cohabitation for males, but not females; high earnings potential strongly boosts the likelihood of marriage for men, but not women; earnings potential affects entry into cohabiting unions for neither sex; and career ambition delays marriage for both sexes. There is clearly a "gender asymmetry" here, especially in relation to marriage, in respect of economic resources: men need such resources, but women not necessarily. The finding on the effect of career ambition, placed alongside the finding that high educational expectations also delay marriage, suggests that for some people personal achievement takes priority over family life, slowing entrance to marriage.

The study's concluding chapter, summarizing and discussing the implications of the research, is happily free of methodological language. The authors set out the characteristics of those who participated in the rise of cohabitation. It was not the well-educated and wealthier families that led the way; the trend was not notably associated with a particular religious affiliation; it was associated with coming from less religious families, with socialization in families where premarital pregnancy and/or divorce had occurred, with sexual precociousness, with mothers holding egalitarian sex-role attitudes, with coming from "nonconforming" families, and with coming from families more integrated into nonfamily than into family networks.

The time that has elapsed between the completion of data collection and publication—14 years—should be mentioned. Obviously research of this complexity takes time to produce, and elements of it have been published in journals along the way. The cohort under scrutiny, however, is one whose union-formation decisions were largely made in the mid- to late 1980s, and with a rapidly evolving phenomenon like cohabitation the reader may wonder what changes have occurred over a further 15-20 years. In Australia, for example, 30 percent of first marriages in the early 1980s were preceded by cohabitation, but that figure had risen to 74 percent by 2005. The American trend may have been less stark, but when in their final chapter the authors repeatedly claim to be painting a picture of "today," one does hanker for a little speculation as to what changes a couple more decades of water under the bridge might have brought.

I would like to end on a positive note, however. I greatly enjoyed the book. Marriage and Cohabitation makes a major contribution to research on contemporary union-formation trends and determinants in the United States. It sets a high standard for research in other developed-country settings to aspire to—even assuming that longitudinal data at all comparable to the IPS could be found. It is a must-read for those with a scholarly interest in contemporary family-formation trends in the United States and other developed countries. Neither would I discourage the "intrigued general reader" from accepting the challenge of grappling with it.

Gordon A. Carmichael is a Fellow at the National Centre for Epidemiology and Population Health, The Australian National University